[ubuntu] How to remove sda1 from grub menu

Set up: ssd drive ubuntu and toshiba HDD Windows: Installed windows on Toshiba hdd on a PC with ubuntu already installed. Windows demanded a partition for system reserved. Allocated a 500mb partition but windows did not input any files into it. Not MBR or anything else. Result 500mb became free space located in front of the NTFS partition. Both systems run in mdos mode
Grub menu: Ubuntu : sda1 windows boot loader : sdb2 windows boot loader. Ubuntu booted up fine. sda1 & sdb2 . Both booted windows fine but only mounted in ro mode so unable to use windows files from ubuntu. I spent several weeks trying to get windows to mount rwe but failed. Error messages insisted that windows was hibeated but I had disabled secure boot & fast boot in the bios and fast boot hibeation etc in the os immediately following installation. Eventually I gave up and successfully merged the free space partition with windows ntfs drive. I used boot repair.
New grub menu: Ubuntu : sda1 windows bootloader : sdb1 windows bootloader. sdb1 boots into windows fine including rwx mode. sda1 tries to boot but enters windows boot repair screen. Result: After selecting Ubuntu to boot an error screen appears with S Skip or M manual repair. clicking S goes straight into Ubuntu.
It would appear first, that the small free space partition caused grub to conclude that windows was hibeated when it wasnt and boot repair removed the grub/mbr files from sda1
Is there any way I can remove sda1 from grub to stop this error page from appearing. Is it possible to get grub to chain load directly to sdb1. Please check out the aotations on the info below.

Gksu nautilus 24^th may 2016
GParted 0.18.0 --enable-libparted-dmraid --enable-online-resize
Libparted 2.3

========================================
========================================Delete /dev/sdb2 (ntfs, 146.48 GiB) from /dev/sdb
This is the windows OS but shows on grub menu as sdb1 very confusing
gksu gedit/etc/fstab 24^th may 2016

# /etc/fstab: staticfile system information.
#
# <file system><mount point> <type> <options> <dump> <pass>

#Entry for /dev/sda2:
UUID=c0d626a9-d88d-4023-bf44-4bd62f1e4232 / ext4 errors=remount-ro 0 1
#Entry for /dev/sda6:
UUID=89d8ca57-ce09-40e5-a95e-a80cf4088897 /home ext2 defaults 0 2
#Entryfor /dev/sda1 :
UUID=2826E9C826E9975A /media/System_Reserved ntfs defaults,nls=utf8,umask=0222 0 0 Boots into windows repair screen
#Entry for /dev/sdb1:
UUID=62DA972ADA96F98D /media/System_Reserved_ ntfs defaults,nls=utf8,umask=0222 0 0
#Entryfor /dev/sdb2 : does not appear on grub menu not appear on grub menu
#Entry for /dev/sda5:
UUID=2a1f8105-5cd2-480e-a5c6-5ff9d39efd97 none swap sw 0 0

/dev/disk/by-uuid/28F4EFDDF4EFAB70/mnt/28F4EFDDF4EFAB70 autonosuid,nodev,nofail,x-gvfs-icon=win%20x,noauto,x-udisks-auth 0 0
/dev/disk/by-uuid/105EDF9E5EDF7B44/mnt/105EDF9E5EDF7B44 auto nosuid,nodev,nofail,x-gvfs-show 0 0

happy to provide any further info required. Thanks.